Mass spectrometer systems are well known and are used in the analysis of various materials. Miniature mass spectrometer systems are also known and have applications as field-portable devices for use in the detection of biological and chemical materials such as warfare agents, drugs, explosives and pollutants. They are also used in space exploration and as residual gas analysers. Many systems of reduced size have been developed and micro-engineering methods are increasingly being used in their construction. Mass spectrometer devices consist of three main subsystems; an ion source, an ion filter and an ion counter. It is also important that, in use, the mass spectrometer device operates within a vacuum so as to enable accurate detection of the required material, such that a complete system includes a mass spectrometer device which is provided in an arrangement that allows operation of the device within vacuum conditions. In conventional laboratory based equipment such a vacuum is easily generated using standard vacuum techniques. Further information on the make up of such systems may be found in GB2384908 co-assigned to the assignees of the present invention.
It is also known to provide mass spectrometer devices as portable devices. In fact even before the development of miniaturised mass spectrometer devices, portable devices such as GB2026231 were known. Such a device includes a power pack and a hand held probe, the probe comprising a gas inlet with a porous membrane, an ion source which can also function as an ion pump, a quadrupole ion filter, an ion detector and a chemical getter agent to provide a vacuum within the probe. The spectrometer is intended for detecting chemicals in remote areas and does not require a conventional vacuum system. The system uses the ion source to create the vacuum necessary for operation of the mass spectrometer such that in use as a detector the ion source is configured as a source and during regeneration of the required vacuum the source is configured as a pump. Such modifications to the system that are required to provide the required vacuum necessary for the operation of the mass spectrometer device are cumbersome and complex. There is, therefore, a need to provide an alternative arrangement or system for establishing and operating a mass spectrometer device within a vacuum.